Generally speaking, a cardiac pacemaker is an electrical device used to supplant some or all of an abnormal heart's natural pacing function, by delivering appropriately timed electrical stimulation signals designed to cause the myocardium of the heart to contract or "beat".
Vasovagal syncope is a condition marked by a sudden drop in blood pressure resulting in fainting. It is not only unpleasant for a patient, but potentially dangerous, as fainting may lead to injuries from falls.
Therapy to counteract a vasovagal syncope episode is possible through use of an implanted cardiac pacemaker. What is needed, then, is a reliable means of detecting the onset of a vasovagal syncope episode, so that the pacemaker can deliver the therapy when it is needed.